Re: [ACPI] Re: [PATCH] filling in ACPI method access via sysfsnamespace
From: Alex Williamson
Date: Sun Apr 11 2004 - 22:34:31 EST
On Sun, 2004-04-11 at 16:29, Matthew Wilcox wrote:
>
> It seems unintuitive that you have to read the file for the method to
> take effect. How about having the write function invoke the method and
> (if there is a result) store it for later read-back via the read function?
> It should be discarded on close, of course. A read() on a file with
> no stored result should invoke the ACPI method (on the assumption this
> is a parameter-less method) and return the result directly. Closing a
> file should discard any result from the method.
How's this? It behaves the way you described, but might be doing
some questionable things with the buffer to get there. Is there a
better place to store the return data than back into the buf passed to
write() (aka file->private_data)? Without adding callbacks to
open/close, I'm not sure how else we can dispose of the results on
close. Thanks,
Alex
drivers/acpi/scan.c | 210 +++++++++++++++++++++++++++++++++++++++-
drivers/base/firmware_class.c | 8 -
drivers/i2c/chips/eeprom.c | 3
drivers/pci/pci-sysfs.c | 6 -
drivers/scsi/qla2xxx/qla_os.c | 32 +++---
drivers/video/aty/radeon_base.c | 6 -
drivers/zorro/zorro-sysfs.c | 4
fs/sysfs/bin.c | 5
include/linux/sysfs.h | 6 -
9 files changed, 248 insertions(+), 32 deletions(-)
===== drivers/acpi/scan.c 1.22 vs edited =====
--- 1.22/drivers/acpi/scan.c Tue Feb 3 22:29:19 2004
+++ edited/drivers/acpi/scan.c Sun Apr 11 21:22:45 2004
@@ -25,6 +25,212 @@
static LIST_HEAD(acpi_device_list);
static spinlock_t acpi_device_lock = SPIN_LOCK_UNLOCKED;
+#define to_acpi_device(n) container_of(n, struct acpi_device, kobj)
+#define to_bin_attr(n) container_of(n, struct bin_attribute, attr);
+
+#define LENGTH_OFFSET (PAGE_SIZE - sizeof(acpi_size))
+
+static ssize_t
+acpi_device_write_raw(
+ struct kobject *kobj,
+ struct attribute *attr,
+ char *buf,
+ loff_t off,
+ size_t length)
+{
+ struct acpi_device *device = to_acpi_device(kobj);
+ struct bin_attribute *attrib = to_bin_attr(attr);
+ struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+ struct acpi_object_list *arg_list = NULL;
+ union acpi_object **cur_arg, *args = NULL;
+ acpi_status status;
+ u32 count, i;
+ size_t size;
+
+ /*
+ * Not sure if offsets should be ignored or enforced, suppose we could
+ * pass multiple arguments that way, but this interface already
+ * accepts multiple arguments packed into an acpi_object array
+ */
+ if (off)
+ return -ENODEV;
+
+ /*
+ * For convenience, handle cases where the last argument
+ * is too small.
+ */
+ count = length / sizeof(union acpi_object);
+ if (length % sizeof(union acpi_object))
+ count++;
+
+ if (count) {
+ size = sizeof(struct acpi_object_list) +
+ ((count - 1) * sizeof(union acpi_object *));
+
+ arg_list = kmalloc(size, GFP_KERNEL);
+ if (!arg_list)
+ return -ENODEV;
+
+ memset(arg_list, 0, size);
+ arg_list->count = count;
+
+ args = (union acpi_object *)buf;
+
+ cur_arg = &arg_list->pointer;
+ for (i = 0 ; i < count ; i++)
+ cur_arg[i] = &args[i];
+ }
+
+ status = acpi_evaluate_object(device->handle, attrib->attr.name,
+ arg_list, &buffer);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ if (arg_list)
+ kfree(arg_list);
+
+ memset(buf, 0, PAGE_SIZE);
+ memcpy(buf, buffer.pointer, min((unsigned long)buffer.length,
+ LENGTH_OFFSET));
+ memcpy(buf + LENGTH_OFFSET, &buffer.length, sizeof(acpi_size));
+ acpi_os_free(buffer.pointer);
+ return length;
+}
+
+static ssize_t
+acpi_device_read_raw(
+ struct kobject *kobj,
+ struct attribute *attr,
+ char *buf,
+ loff_t off,
+ size_t length)
+{
+ struct acpi_device *device = to_acpi_device(kobj);
+ struct bin_attribute *attrib = to_bin_attr(attr);
+ struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+ acpi_size prev_length;
+ acpi_status status;
+ size_t size;
+
+ /* Ditto, see comment above */
+ if (off)
+ return -ENODEV;
+
+ memcpy(&prev_length, buf + LENGTH_OFFSET, sizeof(acpi_size));
+
+ if (prev_length) {
+ memset(buf + LENGTH_OFFSET, 0, sizeof(acpi_size));
+ return min((unsigned long)prev_length, LENGTH_OFFSET);
+ }
+
+ status = acpi_evaluate_object(device->handle, attrib->attr.name,
+ NULL, &buffer);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
+ size = min((unsigned long)buffer.length, LENGTH_OFFSET);
+ memset(buf, 0, PAGE_SIZE);
+ memcpy(buf, buffer.pointer, size);
+ acpi_os_free(buffer.pointer);
+ return size;
+}
+
+static void
+create_sysfs_files(struct acpi_device *dev)
+{
+ acpi_handle chandle = 0;
+ char pathname[ACPI_PATHNAME_MAX];
+ acpi_status status;
+ struct acpi_buffer buffer;
+ struct bin_attribute *attrib;
+ int error;
+
+ buffer.length = sizeof(pathname);
+ buffer.pointer = pathname;
+
+ while (ACPI_SUCCESS(acpi_get_next_object(ACPI_TYPE_METHOD, dev->handle,
+ chandle, &chandle))) {
+
+ memset(pathname, 0 , sizeof(pathname));
+
+ status = acpi_get_name(chandle, ACPI_SINGLE_NAME, &buffer);
+ if (ACPI_FAILURE(status))
+ continue;
+
+ attrib = kmalloc(sizeof(struct bin_attribute), GFP_KERNEL);
+ if (!attrib)
+ continue;
+
+ memset(attrib, 0, sizeof(struct bin_attribute));
+
+ attrib->attr.name = kmalloc(strlen(pathname), GFP_KERNEL);
+ if (!attrib->attr.name) {
+ kfree(attrib);
+ continue;
+ }
+
+ strcpy(attrib->attr.name, pathname);
+
+ attrib->size = LENGTH_OFFSET;
+ attrib->attr.mode = S_IFREG | S_IRUSR |
+ S_IWUSR | S_IRGRP | S_IWGRP;
+ attrib->read = acpi_device_read_raw;
+ attrib->write = acpi_device_write_raw;
+
+ error = sysfs_create_bin_file(&dev->kobj, attrib);
+ if (error) {
+ kfree(attrib->attr.name);
+ kfree(attrib);
+ continue;
+ }
+ }
+}
+
+extern struct dentry * sysfs_get_dentry(struct dentry *, const char *);
+
+static void
+remove_sysfs_files(struct acpi_device *dev)
+{
+ acpi_handle chandle = 0;
+ char pathname[ACPI_PATHNAME_MAX];
+ acpi_status status;
+ struct acpi_buffer buffer;
+ struct bin_attribute *old_attrib;
+ struct dentry *dentry;
+
+ buffer.length = sizeof(pathname);
+ buffer.pointer = pathname;
+
+ while (ACPI_SUCCESS(acpi_get_next_object(ACPI_TYPE_METHOD, dev->handle,
+ chandle, &chandle))) {
+
+ memset(pathname, 0 , sizeof(pathname));
+
+ status = acpi_get_name(chandle, ACPI_SINGLE_NAME, &buffer);
+ if (ACPI_FAILURE(status))
+ continue;
+
+ down(&(dev->kobj.dentry->d_inode->i_sem));
+ dentry = sysfs_get_dentry(dev->kobj.dentry, pathname);
+ if (!IS_ERR(dentry))
+ old_attrib = dentry->d_fsdata;
+ else
+ old_attrib = NULL;
+ up(&(dev->kobj.dentry->d_inode->i_sem));
+
+ if (old_attrib) {
+ if (strncmp(pathname, old_attrib->attr.name,
+ strlen(pathname)) != 0)
+ continue;
+
+ sysfs_remove_bin_file(&dev->kobj, old_attrib);
+
+ kfree(old_attrib->attr.name);
+ kfree(old_attrib);
+ }
+ }
+}
+
static void acpi_device_release(struct kobject * kobj)
{
struct acpi_device * dev = container_of(kobj,struct acpi_device,kobj);
@@ -72,6 +278,7 @@
device->kobj.ktype = &ktype_acpi_ns;
device->kobj.kset = &acpi_namespace_kset;
kobject_add(&device->kobj);
+ create_sysfs_files(device);
}
static int
@@ -79,6 +286,7 @@
struct acpi_device *device,
int type)
{
+ remove_sysfs_files(device);
kobject_unregister(&device->kobj);
return 0;
}
@@ -706,7 +914,7 @@
switch (type) {
case ACPI_BUS_TYPE_DEVICE:
result = acpi_bus_get_status(device);
- if (ACPI_FAILURE(result) || !device->status.present) {
+ if (ACPI_FAILURE(result)) {
result = -ENOENT;
goto end;
}
===== drivers/base/firmware_class.c 1.16 vs edited =====
--- 1.16/drivers/base/firmware_class.c Mon Mar 1 20:01:49 2004
+++ edited/drivers/base/firmware_class.c Sun Apr 11 20:16:41 2004
@@ -167,8 +167,8 @@
firmware_loading_show, firmware_loading_store);
static ssize_t
-firmware_data_read(struct kobject *kobj,
- char *buffer, loff_t offset, size_t count)
+firmware_data_read(struct kobject *kobj, struct attribute *attr,
+ char *buffer, loff_t offset, size_t count)
{
struct class_device *class_dev = to_class_dev(kobj);
struct firmware_priv *fw_priv = class_get_devdata(class_dev);
@@ -227,8 +227,8 @@
* the driver as a firmware image.
**/
static ssize_t
-firmware_data_write(struct kobject *kobj,
- char *buffer, loff_t offset, size_t count)
+firmware_data_write(struct kobject *kobj, struct attribute *attr,
+ char *buffer, loff_t offset, size_t count)
{
struct class_device *class_dev = to_class_dev(kobj);
struct firmware_priv *fw_priv = class_get_devdata(class_dev);
===== drivers/i2c/chips/eeprom.c 1.6 vs edited =====
--- 1.6/drivers/i2c/chips/eeprom.c Mon Mar 15 03:38:36 2004
+++ edited/drivers/i2c/chips/eeprom.c Sun Apr 11 20:16:41 2004
@@ -122,7 +122,8 @@
up(&data->update_lock);
}
-static ssize_t eeprom_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
+static ssize_t eeprom_read(struct kobject *kobj, struct attribute *attr,
+ char *buf, loff_t off, size_t count)
{
struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj));
struct eeprom_data *data = i2c_get_clientdata(client);
===== drivers/pci/pci-sysfs.c 1.8 vs edited =====
--- 1.8/drivers/pci/pci-sysfs.c Mon Feb 9 21:55:42 2004
+++ edited/drivers/pci/pci-sysfs.c Sun Apr 11 20:16:41 2004
@@ -63,7 +63,8 @@
static DEVICE_ATTR(resource,S_IRUGO,pci_show_resources,NULL);
static ssize_t
-pci_read_config(struct kobject *kobj, char *buf, loff_t off, size_t count)
+pci_read_config(struct kobject *kobj, struct attribute *attr,
+ char *buf, loff_t off, size_t count)
{
struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
unsigned int size = 64;
@@ -117,7 +118,8 @@
}
static ssize_t
-pci_write_config(struct kobject *kobj, char *buf, loff_t off, size_t count)
+pci_write_config(struct kobject *kobj, struct attribute *attr,
+ char *buf, loff_t off, size_t count)
{
struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
unsigned int size = count;
===== drivers/scsi/qla2xxx/qla_os.c 1.6 vs edited =====
--- 1.6/drivers/scsi/qla2xxx/qla_os.c Wed Feb 18 20:42:35 2004
+++ edited/drivers/scsi/qla2xxx/qla_os.c Sun Apr 11 20:16:41 2004
@@ -435,10 +435,10 @@
int qla2x00_allocate_sp_pool( scsi_qla_host_t *ha);
void qla2x00_free_sp_pool(scsi_qla_host_t *ha);
-static ssize_t qla2x00_sysfs_read_fw_dump(struct kobject *, char *, loff_t,
- size_t);
-static ssize_t qla2x00_sysfs_write_fw_dump(struct kobject *, char *, loff_t,
- size_t);
+static ssize_t qla2x00_sysfs_read_fw_dump(struct kobject *, struct attribute *,
+ char *, loff_t, size_t);
+static ssize_t qla2x00_sysfs_write_fw_dump(struct kobject *, struct attribute *,
+ char *, loff_t, size_t);
static struct bin_attribute sysfs_fw_dump_attr = {
.attr = {
.name = "fw_dump",
@@ -448,10 +448,10 @@
.read = qla2x00_sysfs_read_fw_dump,
.write = qla2x00_sysfs_write_fw_dump,
};
-static ssize_t qla2x00_sysfs_read_nvram(struct kobject *, char *, loff_t,
- size_t);
-static ssize_t qla2x00_sysfs_write_nvram(struct kobject *, char *, loff_t,
- size_t);
+static ssize_t qla2x00_sysfs_read_nvram(struct kobject *, struct attribute *,
+ char *, loff_t, size_t);
+static ssize_t qla2x00_sysfs_write_nvram(struct kobject *, struct attribute *,
+ char *, loff_t, size_t);
static struct bin_attribute sysfs_nvram_attr = {
.attr = {
.name = "nvram",
@@ -473,8 +473,8 @@
/* SysFS attributes. */
-static ssize_t qla2x00_sysfs_read_fw_dump(struct kobject *kobj, char *buf,
- loff_t off, size_t count)
+static ssize_t qla2x00_sysfs_read_fw_dump(struct kobject *kobj,
+ struct attribute *attr, char *buf, loff_t off, size_t count)
{
struct scsi_qla_host *ha = to_qla_host(dev_to_shost(container_of(kobj,
struct device, kobj)));
@@ -491,8 +491,8 @@
return (count);
}
-static ssize_t qla2x00_sysfs_write_fw_dump(struct kobject *kobj, char *buf,
- loff_t off, size_t count)
+static ssize_t qla2x00_sysfs_write_fw_dump(struct kobject *kobj,
+ struct attribute *attr, char *buf, loff_t off, size_t count)
{
struct scsi_qla_host *ha = to_qla_host(dev_to_shost(container_of(kobj,
struct device, kobj)));
@@ -546,8 +546,8 @@
return (count);
}
-static ssize_t qla2x00_sysfs_read_nvram(struct kobject *kobj, char *buf,
- loff_t off, size_t count)
+static ssize_t qla2x00_sysfs_read_nvram(struct kobject *kobj,
+ struct attribute *attr, char *buf, loff_t off, size_t count)
{
struct scsi_qla_host *ha = to_qla_host(dev_to_shost(container_of(kobj,
struct device, kobj)));
@@ -573,8 +573,8 @@
return (count);
}
-static ssize_t qla2x00_sysfs_write_nvram(struct kobject *kobj, char *buf,
- loff_t off, size_t count)
+static ssize_t qla2x00_sysfs_write_nvram(struct kobject *kobj,
+ struct attribute *attr, char *buf, loff_t off, size_t count)
{
struct scsi_qla_host *ha = to_qla_host(dev_to_shost(container_of(kobj,
struct device, kobj)));
===== drivers/video/aty/radeon_base.c 1.12 vs edited =====
--- 1.12/drivers/video/aty/radeon_base.c Fri Mar 5 03:40:50 2004
+++ edited/drivers/video/aty/radeon_base.c Sun Apr 11 20:16:41 2004
@@ -2014,7 +2014,8 @@
}
-static ssize_t radeon_show_edid1(struct kobject *kobj, char *buf, loff_t off, size_t count)
+static ssize_t radeon_show_edid1(struct kobject *kobj, struct attribute *attr,
+ char *buf, loff_t off, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct pci_dev *pdev = to_pci_dev(dev);
@@ -2025,7 +2026,8 @@
}
-static ssize_t radeon_show_edid2(struct kobject *kobj, char *buf, loff_t off, size_t count)
+static ssize_t radeon_show_edid2(struct kobject *kobj, struct attribute *attr,
+ char *buf, loff_t off, size_t count)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct pci_dev *pdev = to_pci_dev(dev);
===== drivers/zorro/zorro-sysfs.c 1.1 vs edited =====
--- 1.1/drivers/zorro/zorro-sysfs.c Sun Jan 18 23:35:41 2004
+++ edited/drivers/zorro/zorro-sysfs.c Sun Apr 11 20:16:41 2004
@@ -47,8 +47,8 @@
static DEVICE_ATTR(resource, S_IRUGO, zorro_show_resource, NULL);
-static ssize_t zorro_read_config(struct kobject *kobj, char *buf, loff_t off,
- size_t count)
+static ssize_t zorro_read_config(struct kobject *kobj, struct attribute *attr,
+ char *buf, loff_t off, size_t count)
{
struct zorro_dev *z = to_zorro_dev(container_of(kobj, struct device,
kobj));
===== fs/sysfs/bin.c 1.12 vs edited =====
--- 1.12/fs/sysfs/bin.c Fri Aug 29 10:40:51 2003
+++ edited/fs/sysfs/bin.c Sun Apr 11 20:16:41 2004
@@ -20,7 +20,7 @@
struct bin_attribute * attr = dentry->d_fsdata;
struct kobject * kobj = dentry->d_parent->d_fsdata;
- return attr->read(kobj, buffer, off, count);
+ return attr->read(kobj, &attr->attr, buffer, off, count);
}
static ssize_t
@@ -63,7 +63,7 @@
struct bin_attribute *attr = dentry->d_fsdata;
struct kobject *kobj = dentry->d_parent->d_fsdata;
- return attr->write(kobj, buffer, offset, count);
+ return attr->write(kobj, &attr->attr, buffer, offset, count);
}
static ssize_t write(struct file * file, const char __user * userbuf,
@@ -109,6 +109,7 @@
error = -ENOMEM;
file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ memset(file->private_data, 0, PAGE_SIZE);
if (!file->private_data)
goto Done;
===== include/linux/sysfs.h 1.32 vs edited =====
--- 1.32/include/linux/sysfs.h Tue Aug 12 09:53:51 2003
+++ edited/include/linux/sysfs.h Sun Apr 11 20:16:41 2004
@@ -21,8 +21,10 @@
struct bin_attribute {
struct attribute attr;
size_t size;
- ssize_t (*read)(struct kobject *, char *, loff_t, size_t);
- ssize_t (*write)(struct kobject *, char *, loff_t, size_t);
+ ssize_t (*read)(struct kobject *, struct attribute *,
+ char *, loff_t, size_t);
+ ssize_t (*write)(struct kobject *, struct attribute *,
+ char *, loff_t, size_t);
};
int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr);
-
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